Mercury 25 HP 4-stroke starting

Discussion in 'Bubba's Outboards' started by bmaultbay, Mar 31, 2007.

  1. bmaultbay

    bmaultbay New Member

    Messages:
    498
    State:
    Clarksville, Tennessee
    I have a 2006 25 HP 4-stroke which is all but impossible to crank the first start of the day. I have had it back to the dealer twice, could not duplicate, started as advertised for them. After the first start, bump the key, and she fires right up. Any ideas or suggestions?
     
  2. ShilohRed

    ShilohRed New Member

    Messages:
    4,339
    State:
    West Tn
    Take the hood off. And look back toward the carb. If theres a little pump there.
    Then all you need to do is give it gas 3 or three times. That is a primer pump When you advance the throttle it squirts gas into the carb being it does not have a choke.
    My 25 Hp Yamaha 4-stroke is the same way. I have a tiller handle on it. So i advance the throttle 2 or three times and it will start each time cold like it warm.
    Also this is in the manual or is the Yamaha.
    Pete
     

  3. bmaultbay

    bmaultbay New Member

    Messages:
    498
    State:
    Clarksville, Tennessee

    I will check for the bulb, and I will try the throttle advance. No mention of either in the owners manual. When you say advance, wide open throttle, then back to idle or start position?
     
  4. ShilohRed

    ShilohRed New Member

    Messages:
    4,339
    State:
    West Tn
    Yes or just as far as it will move while in Neutral is what I do. It does not have to move much to spray the gas in the carb.
    Pete
     
  5. waterwalker

    waterwalker New Member

    Messages:
    604
    State:
    Louisville Ohio
    Sounds like you are loosing your prime, check all fuel conections.
     
  6. craddock1

    craddock1 Active Member

    Messages:
    957
    State:
    TENNESSEE
    i have a 15 four stroke murcury. i advance the gas just slightly. if it does not start in a few spins i advance it just a little more and it starts. if i do not advance the throtle it will run the battery down and not start.
     
  7. bmaultbay

    bmaultbay New Member

    Messages:
    498
    State:
    Clarksville, Tennessee

    Thanks,

    I spent about an hour one morning trying to start, finally had to pull start, started on the third pull. Un sure of the differences between pull start and electric start.
     
  8. Bigun

    Bigun New Member

    Messages:
    234
    State:
    Burnet, TX
    I had a Mercury that acted similarly. In this case I think pumping the bulb to much was flooding the engine. I installed a low pressure electric fuel pump. I could turn the pump on for seven seconds and the engine would start. After the first time you could not bump the switch without it starting.
     
  9. bmaultbay

    bmaultbay New Member

    Messages:
    498
    State:
    Clarksville, Tennessee

    Sounds similiar, did you purchase the pump from a dealer? Was it installed in place of the bulb?
     
  10. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Knowing the mechanics of how a carb functions, it shouldn't matter if you pressurize the fuel system with an electric low pressure pump or the bulb in the line.

    If however, your not getting fuel into the carb, enough to seat the float and stop more fuel from going in, (Pressurize the fuel system), then you'll have some problem.
     
  11. ShilohRed

    ShilohRed New Member

    Messages:
    4,339
    State:
    West Tn
    If its a 4-stroke, And not EFI. And does not have a choke it will have the little pump to spray fuel in the carbs. When you advance the throttle.
    My Yamaha 4-stroke will run the battery down if you do not give it gas before trying to start it for the first time.
    Pete
     
  12. bmaultbay

    bmaultbay New Member

    Messages:
    498
    State:
    Clarksville, Tennessee

    It is an EFI 4-stroke. So, do I need to advance the throttle?
     
  13. ShilohRed

    ShilohRed New Member

    Messages:
    4,339
    State:
    West Tn
    Being EFI It should start right up. does it have the electric fuel pump?
    If not prime the bulb before starting it.
    they get it to fire up without a problem when there.

    Pete
     
  14. bmaultbay

    bmaultbay New Member

    Messages:
    498
    State:
    Clarksville, Tennessee

    How do I determine if it has an electric fuel pump, novice boat owner. The engine ran fine last year. Yes, dealer says no issues with starting. Like to take them out one morning with me, let them pull start.
     
  15. ShilohRed

    ShilohRed New Member

    Messages:
    4,339
    State:
    West Tn
    If it has a electric fuel pump. You should hear it when turning the key on.
    You are pumping up the priming bulb?
    Pete
     
  16. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    If it's an EFI, it has an electric fuel pump, but it still needs primed with the bulb.

    Your electric fuel pump is in a vapor seporator, works much like a carb. It also has a mechanical pump that works off of crankcase pulse, to pull fuel into the vapor seporator.
     
  17. bmaultbay

    bmaultbay New Member

    Messages:
    498
    State:
    Clarksville, Tennessee

    Yes, I do pump up the bulb. My ignition switch is lableled push for choke, the dealer told me my engine does not use that, owners manual says to turn and push. Done both, with and without. Usually end up flooding the engine. If I start out from the beginning pull starting, she will usually fire up on the third pull. Very frustrating, new boat and motor. Even worse is the wifes nagging about it being broke! The only thing I have done to the engine is change the oil, filter, and the lower unit lube. Once I started having these problems, which was the first time I pulled it out after the winter, I replaced the plugs. Not a lot an owner can do on these new fangled things. The only thing different is I went with a heavier weight oil for the summer heat. I am getting desperate enough to change that back to the 30 wt.
     
  18. Mr.T

    Mr.T New Member

    Messages:
    2,553
    State:
    MO
    If it's a new 4-stroke EFI engine, all you should have to do is turn the key and start it.

    You don't need to perform any special tricks to make it start -- no need for advancing the throttle, pushing the choke, monkeying with some internal pump or anything.
    Just turn the key and go.

    And if that doesn't work, take it back to the dealer and demand that they fix it, as there's clearly something wrong. If it's really an EFI model, you should be able to flood it either -- unless you're monkeying with the throttle or choke.

    If you don't get anywhere with the dealer, cut your losses and get rid of the Merc and by a Yamaha or Suzuki instead - those two companies know how to do a 4-stroke and do it right. My Yamaha 115 4-stroke starts up immediately every single time, no matter the weather. I haven't touched the primer bulb in about 8 months either.
     
  19. bmaultbay

    bmaultbay New Member

    Messages:
    498
    State:
    Clarksville, Tennessee

    I am currently out of town, when I return if I am still having the same issues, I am taking it back to the dealer from I purchased it from.
     
  20. olefin

    olefin New Member

    Messages:
    3,908
    State:
    Texas
    100 % right!
    I've had mine over 3 years and never touched the primer bulb.